The currently available electronic mobile devices have become extremely thin and light. Apart from being thin and light, the new-generation electronic mobile devices have also largely improved computation performance. Due to the improved computation performance and the largely reduced overall thickness, an internal space of the electronic mobile devices for disposing electronic elements is also limited. The higher the computation performance is, the more amount of heat the electronic elements produce during operation. Therefore, vapor chambers and heat pipes are widely used to dissipate the heat produced by the electronic elements.
A vapor chambers normally has a rectangle housing, which has a wick structure and a working fluid provided therein. One side of the housing, i.e. the evaporating section, is attached to a heat-generating element, such as a central processing unit (CPU), south/north bridge chipset, or transistor, to absorb heat produced by the heat-generating element and then evaporated. Thereafter, the evaporated heat is dissipated via a condensing section and condensed into liquid due to capillary force, then flowed back to the evaporating section to complete the whole inclosed circulation.
The operating principle of a heat pipe is similar to the vapor chamber ∘ The heat pipe dissipates heat mainly through a vapor-liquid circulation occurred therein. More specifically, the heat pipe has an evaporating and a condensing end. The evaporating end is in contact with a heat generating element, such that the working fluid located at the evaporating end is heated and vaporized. The vaporized working fluid flows through the chamber to the condensing end, at where the working fluid is condensed into liquid. The liquid working fluid then flows back to the evaporating end with the help of a capillary force of the wick structure.
The difference between the heat pipe and the vapor chamber is that the vapor chamber helps spreads the heat in two dimensions across the vapor chamber area (in-plane spreading) and also conducts the heat in a vertical direction (through-plane), but the heat pipe dissipates the heat only in one dimension, i.e. distant heat dissipation. Currently, only one heat pipe or one vapor chamber attached to electronic elements cannot meet the requirement of heat dissipation. It is therefore tried by the inventor to develop how to combine the heat pipe with the vapor chamber to increase the heat transfer effect.